1. Field of the Invention
This invention relates to a film conveying apparatus for automatically leading out and conveying a film such as a rolled microfilm contained in a cartridge.
2. Related Background Art
What is shown in FIG. 1 of the accompanying drawings has heretofore been available as the microfilm leading-out portion of a film conveying apparatus of this type. In such an example of the prior art, a microfilm F wound on a reel core 103 is rotatably mounted in a cartridge 101. A conveyor belt 104 is rotated in the direction of arrow C by a pulley 106, and a pivotable arm 105 is pivotally moved in the directions of arrows A and B to thereby urge the conveyor belt 104 against and away from the microfilm F. Also, a conveying pulley 110 is rotatively driven in the direction of arrow D to rotate a separating gear 107 in the direction of arrow E through the intermediary of a belt 108. A pinch roller 109 cooperates with the conveying pulley 110 to convey the microfilm F while holding the microfilm therebetween.
In the above-described construction, the leading-out and conveyance of the microfilm F is accomplished in the following manner. The pivotable arm 105 is moved in the direction of arrow A, the conveying belt 104 rotated by the pulley 106 is urged against the microfilm F, and the microfilm F is conveyed by the friction force of the conveyor belt 104. Thereupon, the leading end edge of the microfilm F conveyed to the separating gear 107 is taken out by the tooth top of the separating gear 107 and is fed into between the pinch roller 109 and the conveying pulley 110. Thus, the microfilm F held between the pinch roller 109 and the conveying pulley 110 is conveyed by them and advanced into a guide.
However, in the prior-art apparatus described above, if the direction of conveyance by the pinch roller 109 and conveying pulley 110 is inclined, oblique movement of the film occurs and jamming of the film may occur in the conveyance guide. To eliminate this, it is necessary to properly set the direction of conveyance of the film by the pinch roller and the conveying pulley, but when the length of conveyance of the film is taken into account, high accuracy is required and design is difficult and also, cumbersome adjustment becomes necessary.
Also, in such an example of the prior art, when the rotational speed of the conveying pulley 110 is higher than the speed of the conveyor belt 104 and the conveying means changes from the conveying belt 104 to the conveying pulley 110, the two are driven at a time and the conveyor belt 104 becomes a load of conveyance and therefore, a friction force is applied between the microfilm F and the conveyor belt 104, and this has led to a problem that the microfilm or the conveyor belt is damaged.
Further, in such an example of the prior art, when the microfilm F is to be led out, the pivotable arm 105 is moved about a shaft 106a until the conveyor belt 104 is urged against the microfilm F and therefore, the angle of rotation of the pivotable arm 105 in the direction of arrow A varies depending on the roll diameter of the microfilm. That is, when the roll diameter of the microfilm F is great, the angle of rotation of the pivotable arm 105 is small as shown in FIG. 1, but when the roll diameter of the microfilm F is small, the angle of rotation of the pivotable arm 105 is great as shown in FIG. 2 of the accompanying drawings and thus, the fore end (the leading-out end portion) of the pivotable arm 105 comes into a roll containing portion 101a in the cartridge 101.
As a result, in the roll containing portion 101a, a bag portion 111 is formed between the cartridge 101 and the pivotable arm 105, and when the conveyance of the microfilm F is effected with the leading end edge of the microfilm being positioned between the separating gear 107 and the conveyor belt 104, the leading end edge of the microfilm comes into the bag portion 111, and this has led to a problem that conveyance becomes impossible.